1. Field of the Invention
The present invention relates to a pump for an oil well. More particularly, the present invention involves a pump in the form of a pressure differential plunger.
2. Prior Art
Most people in the oil industry are familiar with the pump jack or walking beam type of pump which is used on oil wells. At the lower end of the well, pumping is effected by means of a plunger which reciprocates within a stationary barrel. At the surface, the external unit involves an arm which moves up and down and which is connected to a rod that goes into the ground. This rod is actually a series of sucker rods which connect at the bottom within the plunger which reciprocates within the barrel. Normally, the barrel will have a check valve in the form of a ball adjacent the bottom of the barrel. The prior art plunger also generally has a check valve in the form of a ball valve adjacent the bottom.
The present invention, on the other hand, involves a pressure differential plunger which can be used in conjunction with the pre-existing barrel. However, the plunger of the present invention has a tapered or venturi throat at its lower end to reduce turbulent flow. The plunger of the present invention also involves a pressure differential valve of the ball-type adjacent the top of the plunger.
The prior art does not show or suggest the features of the plunger of the present invention and, more particularly, the manner in which the pressure differential valve is mounted and operates within the plunger.